Process and means for burning cement slurry



April 10, 1934. A. BUSCH 1,954,401

PROCESS AND MEANS FOR BURNING CEMENT SLURRY Filed Nov. 25. 1932 UNITED STATES PATENT OFFICE PROCESS AND MEANS FOR BURNING CEMENT SLURRY Adolphe Busch, Antwerp, Belgium Application November 25, 1932, Serial No. 644,396 In Belgium December 11, 1931 9 Claims. (Cl. 222-'7) This invention relates to the spreading and between the chains for the passage of the jet or apportionment of matter to be dried or calcined jets of slurry, the number of chains in proporintroduced in the form of jets of slurry, in the tion to the deflectors can be considerably inopposite direction to the currents of hot gases in creased, and as a result the length of the kiln rotary kilns such as those employed for the Wet can be reduced without diminishing its output. 6 process manufacture of cement. An important feature of the invention is the To obtain efficiency in these kilns it is imporarrangement of the deflectors so that the slurry tant that the slurry be spread in a finely divided will be automatically apportioned throughout state throughout the drying area of the kiln, the length of the drying zone in a quantity defiin order to ensure intimate contact between the nitely proportional to the temperature of the particles of slurry and the hot gases serving to heating gases at different points in the length dehydrate them. These conditions are partly obof the said drying zone, thus ensuring the best tained by injecting the slurry directly on to employment of the heat from said gases and chains or other analogous members suspended simultaneously drying the slurry to the same within the kiln for the purpose of increasing degree throughout the length of the kiln. This the heating surface, and which break up and result is obtained by disposing the deflectors in spread the jet of slurry by checking its trajechelicoidal rows and by forming them, from the tory during rotation of the kiln. However, these point of entry of the slurry into the kiln, either chains can only be arranged in somewhat reof a width which progressively increases, or else duced number and at a certain distance from with aspacing which gradually decreases, wherethe entrance of the kiln if it is desired to keep by during rotation of the kiln, those deflectors the slurry from bouncing out of the furnace which are situated in the hottest part of the drywhen striking the first set of chains and, for ing Zone remain in the trajec y of j t f this reason an important portion of the drying slurry for a longer time than those in the cooler zone is not effective. Again, at the moment of portion, and receive and spread on the adjacent impact the chains tend to yield and thereby afchains a greater quantity of slurry. In addifect the extent of the dispersion of the jets of tion, it is advantageous to O t a er t slurry, which remain more or less compact. deflectors of one row with respect to those of One of the advantages of the present inventhe adjacent row or rows, tion is that it enables the entire length of the Whatever may be t arrangement o t e dedrying zone to be utilized effectively, and when fiectors, it follows that the violent impact of the chains are used it also enables this length to jet of slurry thereon tends not only to scatter be reduced by increasing the number of chains the slurry in drying particles, but also t expel which can be used. Afurther advantage is gaina considerable quantity of the water contained ed by the absence of any yielding of the chains h r 80 t at th d y a t n Of the hot against which the slurry now impinges with less gases takes effect upon particles of slurry already f r e than heretofore, partly dehydrated, heat consumption thereby be- According to the process according to my ining reduced. vention, matter such as slurry is injected in one The invention is equally applicable to kilns or more jets on to one or more series of rigid provided with long or short chains suspended in deflectors located within the kiln in such mansuch manner as to leave a free space for the ner as to be presented in succession to said jet passage of jets of slurry towards the de- 01' jets which jets are wholly broken up by imflectors. It is preferable to employ chains suspact therewith, the particles of slurry reboundpended from one extremity, and to form them, ing therefrom at a relatively slow speed through both at the entrance and the exit of the drying 109 the heating gases. zone, of a length greater than the radius of the These deflectors may be employed in conjunckiln and of a shorter length intermediately of tion with or without chains as desired, and if said the drying zone. In this case the rows of dedefiectors are appropriately inclined, it is possible fiectors are disposed on the inner walls of the to control the rebound of the slurry in such kiln and the slurry is injected at the lower part manner that when chains are employed, those thereof. The long chains prevent the reboundchains located immediately at the entrance of ing slurry from leaving the drying zone, while the kiln are sprinkled indirectly without the the shorter chains are not struck until after the slurry rebounding from the kiln. In addition, particles of slurry have traversed a relatively as it is no longer necessary to maintain spaces long upward trajectory. 110

The invention will be described hereinafter with reference to the accompanying drawing in which it is illustrated and in which Fig. 1 is a diagrammatic vertical cross section of a rotary kiln according to the invention.

Fig. 2 illustrates diagrammatically part of the inner wall of a kiln with deflective surfaces of increasing width placed at equal distances.

Fig. 3 is a like view of the inner wall of a kiln with deflective surfaces of equal width but placed at varying distances.

Fig. 4 is a cross section on line I-I of Fig. 1.

Fig. 5 is a view of the forward end of the kiln.

As shown in the drawing, 1 is the wall of the rotary kiln, lined interiorly with insulating layer 1 which in turn is forced with a metallic plate doubling 1. Long chains 2 are fitted at the forward end of kiln in such manner that the jets of slurry 6 projected by nozzles 3 have a clear passage below these chains. In order to obtain an economical exchange of heat over the remaining part of the drying area, a desired number of short chains are fitted in such manner as to catch these splashing and rebounding particles of slurry which are still insufi'iciently dehydrated. Rows '7 of long chains define the limits of the heating area. 5; 5a-5e and 5', 5a 5e indicate the deflecting surfaces fixed to the inner wall of the kiln on to which the jets of slurry are projected and from which they rebound.

These sets of deflecting surfaces are offset relativelyto each other. The deflecting surfaces themselves are inclined and may be fitted with such inclination to the direction of jet or jets and may be so shaped that the jets of slurry will be scattered in a more or less horizontal or vertical direction as desired, in order to ensure a proportional distribution of slurry at all points of the heating area.

With the purpose of distributing the slurry in quantities substantially commensurate with the temperature prevailing at each point in the heating area, the equidistant deflecting surfaces increase in width towards the inlet of gases, whose direction of flow is indicated by arrow 3 (Fig. 2), or else when said deflecting surfaces are of same width, the clearance between two surfaces of the same set decreases. In this way more slurry is dispensed at the point of gas inlet, where a higher temperature prevails than adjacent the gas outlet, thereby ensuring uniform drying of any material treated.

I claim:

1. In a process of feeding and distributing slurry to be burned in a rotary kiln by wet process having a drying area, blowing hot gases through said drying area towards the feeding end thereof, injecting said'slurry into said area in a direction substantially parallel with the longitudinal axis of said area and against the direction of flow of said hot gases and projecting indirectly said slurry on the wall of kiln.

2. In a process of feeding and distributing slurry in a rotary kiln by wet process having a drying area and chains arranged in said area, blowing hot gases through said area towards the feeding end thereof, injecting said slurry into said area in a direction substantially parallel with the longitudinal axis of said area and against the direction of flow of said hot gases and projecting indirectly said slurry on said chains.

3. In a rotary kiln heated by an inflow of hot gases, a drying area for the treatment of slurry, means for injecting said slurry against the direction of flow of said hot gases and deflecting surfaces fixed on the inner wall of kiln so as to deviate the jet of slurry on said wall of kiln.

4. In a rotary kiln heated by an inflow of hot gases, a drying area for the heat treatment of slurry, means for injecting said slurry against the direction of flow of said hot gases, chains arranged in said area and deflecting surfaces fixed on the inner wall of kiln so as to deviate the jet of slurry on said chains.

5. In a rotary kiln heated by an inflow of hot gases, a drying area for the heat treatment of slurry, means for injecting said slurry against the direction of low of said hot gases, deflecting surfaces fixed on the inner wall of kiln, the width of said deflecting surfaces increasing in the direction of inlet end of said hot gases in the kiln.

6. In a rotary kiln heated by an inflow of hot gases, a drying area for the heat treatment of slurry, means for injecting said slurry against the direction of flow of said hot gases, deflecting surfaces fixed on the inner wall of the kiln, said deflecting surfaces being of equal width and placed with decreasing intervals in the direction of inlet end of said hot gases.

7. In a rotary kiln heated by an inflow of hot gases, a drying area for the heat treatment of slurry, means for injecting said slurry against the direction of flow of said hot gases, deflecting surfaces fixed on the inner wall of the kiln, said deflecting surfaces being arranged in several sets offset relatively to each other.

8. In a rotary kiln heated by an inflow of hot gases, a drying area for the heat treatment of slurry, means for injecting said slurry against the direction of flow of said hot gases, deflecting surfaces fixed on the inner wall of the kiln and arranged in several sets offset relatively to each other, said deflecting surfaces being shaped so that the rebounding particles of slurry are directed in any given direction.

9. In a rotary kiln heated by an inflow of hot gases, a drying area for the treatment of slurry,

means for injecting said slurry against the direction of flow of said hot gases, chains suspended in said area, deflecting surfaces fixed on the inner wall of the kiln so as to deviate the jet of slurry on said chains, said chains in the part intermediate the drying area above the said deflective surfaces being of shorter length than those suspended at the hot gases inlet and outlet ends.

ADOLPHE BUSCI-I.

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